Protein Levels in Races of Silk Worm Bombyx Mori (Linnaeus) Parasitized by Uzi Fly, Exorista Sorbillans (Wiedemann)

The physiological status of parasitized silk worm can be evaluated in terms of their protein levels. In the fifth instar of the silk worm, Bombyx mori (L.) parasitized with uzifly, Exorista sorbillans (Wiedemann), total proteins in the haemolymph and fat bodies initially increased on 3rd day in and PM x NB4D2 races followed by decrease from 4th to 6th day. In NB4D2 race, a progressive decrease was observed from 3rd to 6th day. The free amino acid (FAA) level increased from 3rd to 4th day, and decreased from 5th to 6th day. Similar was the case with activities of protease, aspartate amino transferase (AAT), alanine aminotransferase (AlAT) and uric acid levels which increased from 3rd to 6th day. This was unlike the glutamine dehygrogenase (GDH) which decreased on 3rd day and increased from 4th to 6th day. These results indicate domination of protein synthesis over breakdown on 3rd day of parasitization in PM and PM x NB4D2 races. Decrease in total proteins of haemolymph and fat bodies from 4th to 6th day in PM race and PM x NB4D2 hybrid, and from 3rd to 6th day in NB4D2 races indicate their breakdown under the parasitized stress conditions. Increase in AlAT, AAT and GDH enzyme activities could indicate the active trans deamination reactions. Correlated with changes in proteins, a decrease was observed in the length and weight of uzi fly parasitized worms, with black scars all over the body. The cocoon size also greatly decreased along with a significant decrease in the strength and length of silk filament. These results indicate greater resistance in PM race to uzi fly parasitization compared to NB4D2 race and PM x NB4D2 hybrid. Of these PM x NB4D2 hybrids appeared more tolerant than pure NB4D2 race.